Many years ago, manufacturers learned that, when building sufficiently large quantities of identical products, assembly lines could be used to increase the rate of production and decrease the per-unit production costs. In an assembly line, the assembly process is divided in a series of processing steps through which the work-in-process moves to result in the end product. These steps may be optimized, and once the manufacturing system becomes operational it will build a number of products with the same configuration using the optimized steps.
Assembly lines are typically used in a build-to-stock production model, where large quantities of identical products are manufactured in anticipation of forecasted demand. The manufactured products are then warehoused until that demand is realized. Build-to-stock manufacturing systems are therefore primarily suited to markets in which manufacturers can accurately predict customer demand.
In many markets, however, predicting customer demand is risky, at best. For example, in the market for computer systems and related items, technological improvements are realized so frequently and component prices change so rapidly that it is difficult to accurately predict how large the market for any particular product will ultimately be. As a result, when manufacturers in industries like information technology utilize the build-to-stock model, those manufacturers frequently find themselves with stocks of manufactured goods that are difficult or impossible to market at a profit (i.e., with stale inventory).
A contrasting model of production that helps manufacturers avoid the stale-inventory problem is the build-to-order model. According to the build-to-order model, each product is assembled only after a customer has ordered that particular product. One of the disadvantages traditionally associated with the build-to-order model, however, is that more time is required to fill orders, in that products must be manufactured, not simply taken from stock. Another disadvantage is that build-to-order manufacturing systems are typically less efficient than build-to-stock manufacturing systems, which drives up the cost of products that are built to order. Accordingly, build-to-order systems have typically been utilized in markets for luxury items, such as tailored clothing, and markets in which a paucity of manufacturers leaves consumers with little choice but to bear the high prices and delays that are generally passed down by build-to-order manufacturers.
Some manufacturers have attempted to minimize the delays associated with the build-to-order model by maintaining a significant inventory of the materials required for production (e.g., the components that are assembled to create the finished goods). Simply carrying such an inventory, however, imposes costs on manufacturers, including the costs associated with warehousing the material. Furthermore, in markets where product innovations occur rapidly, such material oftentimes become stale.
For example, in contemporary times, the market for computer systems (including, without limitation, mini-computers, mainframe computers, personal computers, servers, work stations, portables, hand held systems, and other data processing systems) has been marked by high and increasing rates of product innovation. Further, to manufacture, for example, a typical personal computer, many different components are required, including a processor, memory, additional data storage (such as a hard disk drive), a number of peripheral devices that provide input and output (I/O) for the system, and adapter cards (such as video or sound cards) for communicating with the peripheral devices. Each of those components is also typically available in many different variations. In such markets, even if using the build-to-order model, manufacturers risk significant losses when carrying significant inventories of material.
Also, it is difficult to optimize build-to-order manufacturing facilities in terms of labor requirements and space requirements, as such facilities must be able to produce of a wide variety of products. However, in markets where many manufacturers are competing for customers, such as the computer system market, any reduction in production costs that does not decrease product quality is an important improvement.
Among the cost-saving measures that a producer may employ is to follow the direct-ship model, in which the manufacturer avoids middlemen such as distributors and retailers by accepting orders directly from and shipping products directly to customers. However, additional costs are borne by a manufacturer that provides a directs-ship option, in that the manufacturer must provide distribution facilities, in addition to providing the manufacturing facilities.